3682. Two machines produce the same parts, which are fed to a common conveyor. The performance of the first machine is twice the performance of the second. The first machine produces an average of 60% of parts of excellent quality, and the second - 84%. Randomly taken from the conveyor part was of excellent quality. Find the probability that this part is produced by the first machine gun.

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)